How Saliva Helps Protect Against Cavities

We have all heard the drill for preventing cavities. Brush your teeth every morning and before bed. Floss every day. Dentists often also rely on sealants and fluoride treatments to guard against cavities and lower the odds of root canal therapy. While these interventions are generally effective, dentists may be overlooking something important in the battle.

Cavity-producing bacteria produce a biofilm on the surface of our teeth, which allows them to bind to our teeth. While inside this protective biofilm, the bacteria is able to thrive, feeding on the sugars. The bacteria produces acid as a byproduct. This acid weakens and wears away our natural tooth enamel, eventually producing cavities and tooth decay.

Our saliva is made up primarily of water. But the 0.5% of saliva that is mucus performs a vital function in our fight against cavities. This mucus contains salivary mucins, compounds that play an active role in protecting us from the effects of the harmful bacteria.

Salivary mucins allow the mucus to catch the bacteria and leave it suspended in liquid so that it cannot bind to the teeth and form a biofilm. If the bacteria cannot attach itself to the teeth, it cannot produce cavities. Further, the mucus does not disturb the healthy bacteria in our mouths.

The usefulness of our saliva shines a spotlight on the implications of dry mouth. Those suffering from a lack of saliva are known to have a harder time fighting tooth decay. Dry mouth is a common side effect of certain medications. Certain medical conditions such as cystic fibrosis, ulcerative colitis and asthma are also associated with lower levels of cavity-preventing mucins.

Cavity prevention strategies, then, should include remedies for dry mouth. One way to increase saliva production is to chew sugar-free gum. A prescription or over-the-counter saliva substitute may also help.